Non-Point Pollution from Crop Production： Global,Regional and National Issues

China is now the world＇s largest producer and user of industrial fertilizers and manures. Consequently China plays a substantial role in global N cycle dynamics and in man＇s disruption of the nitrogen cycle though there are still significant uncertainties about the size and importance of emission and leaching rates. A major cause of China＇s global role is the overuse of nitrogen fertilizers, which is most serious with intensive vegetable production where application rates can be up to 50% greater than crop needs, but is also a problem with wheat, rice and maize. China＇s overuse of nitrogen fertiliser over the past 10-20 years has resulted in non-point source （NPS） pollution from crop production becoming a major cause of water pollution, and the situation is projected to get worse. In contrast, water pollution from point sources such as intensive livestock production and urban or industrial development is being brought more under control. The consequences for air pollution are equally serious. Emissions of nitrous oxide from fertilizers and manures may be so large that China could be responsible for 25-30% of global emissions of this damaging greenhouse gas and of the global warming resulting from it. The main national and local issues relate particularly to low fertilizer use efficiency and the losses of ammonia and NOx that lead to acid precipitation, and leaching and run-off losses that result in high nitrate levels in groundwater and eutrophication of rivers and lakes. The reasons why farmers overuse nitrogen fertilizer are complex and not fully understood. They involve agro-climate differences between provinces and counties, farming systems and farm income structures. Although there is a wide range of institutional and technological improvements that can greatly reduce this overuse rapid progress in reducing NPS is unlikely.     

How Much Does the Presence of a Competitor Modify the Within-Canopy Distribution of Ozone-Induced Senescence and Visible Injury?

Many natural vegetation species have been shown to be negatively affected by ozone. This study has investigated how the presence of competing species in a community affects two common responses to ozone: visible injury and senescence. Monocultures and mixtures of Trifolium repens and Lolium perenne were grown in large containers and were exposed in solardomes to either a rural episodic ozone profile (AOT40 of 12.86 ppm h) or control conditions (AOT40 of 0.02 ppm h) for 12 weeks. The proportion of ozone-injured or senesced leaves was different in the different regions of the canopy. The highest proportions of injured/senesced leaves were in the plant material growing at the edge of the canopy and the upper canopy, with a significantly lower proportion of injured leaves in the inner canopy. The presence of L. perenne increased the proportion of ozone-injured leaves in T. repens at the final harvest, whilst the presence of T. repens decreased the proportion of senesced leaves in L. perenne. In L. perenne, the proportion of injured leaves at the edge and inner canopy decreased significantly when grown in competition, whilst for T. repens the reverse effect occurred in the inner canopy only. Different mechanisms appeared to influence the interaction between response to ozone and competitors in these two species. In L. perenne the response to ozone may have been related to nitrogen supply, whereas in T. repens canopy structure was more important.     

Global protected areas and IUCN designations: Do the categories match the conditions?

Protected areas are considered fundamental to the preservation of nature. The International Union for Conservation of Nature (IUCN) has standardized categories for protected areas designation, which are intended to represent varying levels of regulatory protection. We evaluate whether the present assignment of protected areas to IUCN categories corresponds to the expected gradient of naturalness in a globally consistent manner. Our proxy of naturalness was a global map of human influence known as Human Footprint (HF). Higher HF values represent less intact natural areas. Our final sample of protected areas included 21,186 IUCN-designated sites that were ?1 km². We used multiple linear regression to test for the effect of IUCN categories on mean HF while accounting for biome and protected area size.The present assignment of protected areas to IUCN categories does not correspond to the expected gradient of naturalness. We observed that IUCN Category Ia areas have higher HF than expected and Category VI protected areas have unexpectedly low HF; Category VI protected areas also are generally larger than protected areas of other categories. Reporting of area protected in different IUCN categories is one measure of progress towards meeting commitments under the Convention on Biological Diversity, yet because IUCN categories are not interpreted consistently across the globe, this is not a reliable metric. Further, despite the social, economic and ecological importance of protected areas with a very low HF, our results suggest that the availability of such areas within the global protected areas network is very limited.     

The United States energy dilemma: How can we solve it?

Water, Air, & Soil Pollution - The basis for the present energy dilemma is described. The current solution to the inadequate petroleum and natural gas supplies and possible long-term solutions...     

How well do fertilizer enhancers work?

Fertilizer enhancers can provide economic and environmental benefits but their efficacy needs to be assessed appropriately. This study analyzed available trial results of three different fertilizer enhancer products to determine if the results support product claims. All available trial results were considered for a meta-analysis of each product. Product effect was calculated for each experiment in a manner that could be compared with manufacturer claims. The distribution of trial results was examined and factors that may have influenced results assessed. Previously published assessments of the products were compared. N-Boost biostimulant sprayed with dissolved urea increased pasture nitrogen response by an equivalent of 18.0 kg N/ha compared to urea alone in nitrogen-responsive and label-conditions trials. For SustaiN Green urease-inhibitor-treated urea, pasture nitrogen response was 50% higher than untreated urea if low-ammonia-volatilization-risk trials were excluded. AVAIL phosphate fertilizer enhancer increased crop yields by 4.1% over untreated fertilizer in fertilizer-responsive and non-high-soil-phosphate trials.     

How many plant species are cultivated?

Cultivation reflects an intense relationship between human and plants. Therefore, the number of cultivated plant species is of general interest. The number of cultivated crop species amounts to about 7,000 (“Mansfeld’s approach”). Amenity horticulture is a quickly developing area comprising ornamentals and other plants connected with gardening and landscaping. 28,000 plant species have been estimated to belong to this group. Cultivated forest plants are partly included in the first group and mostly in the second group. Thus, we propose that the total number of cultivated plants amounts to 35,000 species, i.e. about 14% of the number of higher plant species of the world.     

How successful are plant species reintroductions?

Reintroduction of native species has become increasingly important in conservation worldwide for recovery of rare species and restoration purposes. However, few studies have reported the outcome of reintroduction efforts in plant species. Using data from the literature combined with a questionnaire survey, this paper analyses 249 plant species reintroductions worldwide by assessing the methods used and the results obtained from these reintroduction experiments. The objectives were: (1) to examine how successful plant species reintroductions have been so far in establishing or significantly augmenting viable, self-sustaining populations in nature; (2) to determine the conditions under which we might expect plant species reintroductions to be most successful; (3) to make the results of this survey available for future plant reintroduction trials. Results indicate that survival, flowering and fruiting rates of reintroduced plants are generally quite low (on average 52%, 19% and 16%, respectively). Furthermore, our results show a success rate decline in individual experiments with time. Survival rates reported in the literature are also much higher (78% on average) than those mentioned by survey participants (33% on average). We identified various parameters that positively influence plant reintroduction outcomes, e.g., working in protected sites, using seedlings, increasing the number of reintroduced individuals, mixing material from diverse populations, using transplants from stable source populations, site preparation or management effort and knowledge of the genetic variation of the target species. This study also revealed shortcomings of common experimental designs that greatly limit the interpretation of plant reintroduction studies: (1) insufficient monitoring following reintroduction (usually ceasing after 4 years); (2) inadequate documentation, which is especially acute for reintroductions that are regarded as failures; (3) lack of understanding of the underlying reasons for decline in existing plant populations; (4) overly optimistic evaluation of success based on short-term results; and (5) poorly defined success criteria for reintroduction projects. We therefore conclude that the value of plant reintroductions as a conservation tool could be improved by: (1) an increased focus on species biology; (2) using a higher number of transplants (preferring seedlings rather than seeds); (3) taking better account of seed production and recruitment when assessing the success of reintroductions; (4) a consistent long-term monitoring after reintroduction.     

Canadian Power Stations and the National Pollutant Release Inventory (NPRI): A Success Story for Pollution Intensity?

This paper presents a comprehensive analysis of the pollutant emissions and intensity from Canada’s power stations. An analysis of National Pollutant Release Inventory (NPRI) and site generation data shows significant variability with the dominant emissions pathway being point-source air emissions. In general, power stations are a very small fraction of Canada’s direct facility and estimated diffuse emissions, as well as showing significant variability of pollutant intensities per megawatt or megawatt hour of capacity or generation. The evidence also suggests that increased scale does not lead to a lower pollutant intensity, and that transfers and disposal pollutant loads are substantial, often representing most of the total reported pollutants. Overall, this study provides a valuable insight into the current status of pollutant intensities from Canada’s power stations, possible improvements to the NPRI and a valuable benchmark for future studies and international comparisons.     

Assessing replacement cost of conservation areas: How does habitat loss influence priorities?

Replacement cost refers to the loss incurred if the ideal set of conservation areas cannot be protected due to compulsory inclusion or exclusion of some area candidates. This cost can be defined either in terms of loss of conservation value or in terms of extra acquisition cost, and it has a clear mathematical definition as a difference between the value of the unconstrained optimal solution and a constrained suboptimal solution. In this work we for the first time show how replacement cost can be calculated in the context of sequential reserve selection, where a reserve network is developed over a longer time period and ongoing habitat loss influences retention and availability of sites. In case of site exclusion, a question that can be asked is, “if a site belonging to the ideal (optimal) solution cannot be obtained, what expected loss in reserve network value does this entail by the end of the planning period given that the rest of the solution is re-organized in the most advantageous manner?” Heuristically, the proposed method achieves the ambit of combining irreplaceability and vulnerability into one score of site importance. We applied replacement cost analysis to conservation prioritization for wood-inhabiting fungi in Norway, identifying factors that influence replacement cost and urgency of site acquisition. Among other things we find that the reliability of loss rate information is important, because the optimal site acquisition order may be strongly influenced by underestimated loss rates.     

Statistical power and sea turtle nesting beach surveys: How long and when?

Identifying long-term population trends is essential for the conservation of species of concern. With money and personnel often in short supply, the success of a monitoring program to provide an estimate of population trend requires an efficient survey design that can detect biologically important changes within some prescribed budgetary framework. In this paper we illustrate how costs can be reduced while maintaining an efficient design using a nesting beach survey of female hawksbill sea turtles (Eretmochelys imbricata) in the Eastern Caribbean as a specific example. We compared the statistical power of the current, intensive protocol with those of shorter duration and differing start date to generate general guidelines on sampling. Counts of individual turtles from 1987-2003 were analyzed using Poisson log-linear regression and models with both fixed and random effects describing the temporal variability were explored. We estimate that the current 20 week saturation-tagging survey design could detect a 3% per annum growth with acceptable statistical power (>0.8) in less than 14 years. However, by changing the current survey start date and counting for only 10 weeks, it is possible to detect similar trends with little loss of power while reducing monitoring costs by 25-50%. Our analyses indicate that the statistical power of surveys for hawksbills is influenced by the timing and duration of the survey because of their effect on the proportion of the annual number of nesting females that the survey captures. This simplifies estimating the power of a prospective survey program.     

Reactions to soil acidification in microarthropods: Is competition a key factor?

Summary Acidification of raw humus soil in coniferous forest areas leads to characteristic changes in the microarthropod community. Certain species are calciophilic and decrease in abundance, while others are acidophilic and increase in abundance. The simplest explanation for these changes is that population levels are directly related to soil pH. This hypothesis was tested by growing small populations of selected species in monoculture at different pH levels. Three acidophilic species were tested, the collembolan Mesaphorura yosii, the oribatid mite Nothrus silvestris, and the astigmatid mite Schwiebea cf. lebruni. A slightly calciophilic collembolan, Isotomiella minor, was also included. For all species, population growth was lowest in acidified raw humus. Even acidophilic species seem to have an optimum at a high pH. It is assumed that their success in low-pH soils is due to their ability to compete under these conditions. Competition may be a key factor in microarthropod reactions to soil acidification.Dedicated to the late Prof. Dr. W. Kühnelt     

How can the fipronil insecticide access phloem?

Seeds of sunflower plants coated with the fipronil (14)C-insecticide were allowed to grow in the greenhouse. The distribution of the (14)C-compounds was studied in each part of the plant after three months. After 83 days of culture small amounts of (14)C-compounds were found in the inflorescence (0.6 per thousand of the seed deposit) which were fipronil itself or its lipophilic or hydrophilic metabolites. The (14)C-compounds were found in each part of the inflorescence (bracts, ray and disk florets containing pollen, akenes). The (14)C-concentration in the xylem sap evaluated at this stage was much too low to explain the accumulated amount in the inflorescence. Under controlled conditions in a culture chamber, it was then demonstrated that a net phloem transfer of (14)C-fipronil occurred from developed leaves to growing organs. This allowed us to suppose that a similar (14)C-fipronil phloem transfer could occur toward the inflorescence during its formation. A quantitative evaluation suggests that most of the labeled compounds at this stage were not coming from the leaves but from the roots and stem where storage compounds were hydrolyzed for sustaining inflorescence development.     

Discussion Paper: Boron — How can the Critical Level be Defined?

The correct diagnosis of boron deficiency is not yet completely resolved for species where boron is phloem immobile. As some deficiency reactions in the extension zone of young roots cannot be reversed after only one hour of deficiency, boron should be supplied continuously. Several early deficiency reactions are shown to be related to the concentration of ”︁free” boron. It is suggested that there is a ”︁minimum” or ”︁critical level” of soluble boron (i.e. not tightly bound to rhamno‐galacturonan II) which is needed in the most boron requiring tissues to avoid deficiency reactions. Determination of this ”︁soluble” or ”︁exchangeable” boron fraction might improve the diagnosis of boron deficiency.     

Cropping leads to loss of soil organic matter: How can we prevent it?

<正>Soil organic matter (SOM), which associates carbon (C) to key plant nutrients, has been stored in soil for thousands of years. Scientists have long recognised its positive impact on key environmental functions such as food production and climate regulation. As soon as a virgin land (forest or grassland) is cultivated, there is a tendency for the soil to lose its SOM, and we still largely misunderstand the underlying mechanisms, leading to inappropriate decisions being taken to fight soi...     

Frogs under friendly fire: How accurately can the general public recognize invasive species?

Members of the general public interact with wildlife in many ways, and an inability to distinguish between species can have significant implications for conservation. For example, attempts by environmentally-concerned private citizens to control invasive species may cause collateral damage unless people can reliably distinguish native fauna from the invader. We tested the Australian public’s ability to distinguish invasive cane toads (Bufo marinus) from native frogs at egg, tadpole, subadult and adult life-history stages. Errors were common, especially for eggs and tadpoles (27-31% error rates) and less so for subadult and adult toads and frogs (5-43% error rates). Accuracy of identification was higher in people living in areas where toads occur (compared to other parts of Australia or overseas), and similar in men and women (but with a decrease in older men). Ability to identify anurans was increased by toad-identification awareness programs and membership of “toad-busting” community groups, but direct killing of cane toads by the general public may inflict substantial “friendly fire” on native frogs. In the absence of any clear evidence for ecological benefits from toad-killing, we suggest that such collecting activities should be conducted only in areas where toads are known to occur, and under the supervision of trained personnel (to identify any anuran before it is killed), rather than as an ad hoc activity pursued independently by local residents. More generally, conservation activities that involve public participation should carefully evaluate the potential rates and consequences of species misidentification by well-intentioned but untrained people.     

Concordance of stream macroinvertebrate assemblage classifications: How general are patterns from single-year surveys?

We examined how the assemblage structure and assemblage-environment relationships of stream macroinvertebrates varied over three consecutive years in a boreal drainage system. We specifically examined whether classifications produced assemblage types that were stable through time, and how these assemblages could be predicted based on local environmental variables. We also used a combination of Procrustes rotation analysis and NMDS ordinations to examine the degree of year-to-year concordance of assemblage patterns. The composition of site clusters varied among years, resulting in only moderate among-year concordance of assemblage classifications. Stream width and in-stream habitat conditions, especially macrophyte cover, were the most important variables discriminating among the cluster groups. Despite temporally variable assemblage classifications, the overall macroinvertebrate assemblage structure was concordant among years. Among-year concordance was higher in-streams with low temporal variation in the physical environment, as well as high abundance and low variability of macrophytes. Due to among-year variability in cluster composition and weakly predictable assemblage-environment relationships, a posteriori assemblage classifications may be of limited value in the conservation planning of headwater streams.